The Diagnosis of Spontaneous Coronary Artery Dissection by Optical Coherence Tomography

[Cardiac magnetic resonance imaging and coronary optical coherence tomography : Acquisition techniques, interpretation and integration in diagnostic algorithms for MINOCA]

MINOCA is a heterogeneous entity with many possible etiologies that need to be clarified to optimize therapeutic interventions. Common causes include plaque disruption, plaque erosion, spontaneous coronary artery dissection, coronary artery spasm, coronary thromboembolism. Most of the time, coronary angiography is inadequate to obtain the proper identification of these underlying pathophysiological mechanisms. Within this context, myocardial tissue characterization with magnetic resonance imaging is key investigation to assess and locate recent myocardial infarctions and to exclude differential diagnostics such as myocarditis or takotsubo cardiomyopathy. In addition, optical coherence tomography is a powerful tool to visualize coronary intraluminal and superficial coronary artery structures in detail including the detection of plaque disruption signs, thrombus or dissections. The use of appropriate diagnostic algorithms combining both OCT and CMR seems to provide a clear substrate or diagnosis to many of the cases. This narrative review aims to expose both imaging modalities focusing on their contributions in the setting of MINOCA.

Spontaneous Coronary Artery Dissection: An Underdiagnosed Clinical Entity-A Primer for Cardiac Imagers

Spontaneous coronary artery dissection (SCAD) is a nonatherosclerotic cause of myocardial infarction in young and middle-aged women that has gained increasing awareness in recent years. Its diagnosis presents a challenge. Invasive coronary angiography is the primary imaging modality for diagnosing SCAD; however, it carries risk in these patients, who have an increased predisposition to complications. Advances in CT technology enable robust noninvasive evaluation of the coronary arteries at low radiation doses and have been increasingly utilized for the diagnosis or resolution of SCAD, in hemodynamically stable patients or when diagnosis of SCAD is uncertain at invasive angiography, particularly in proximal vessels. However, criteria for the diagnosis of SCAD with use of coronary CT angiography (CCTA) have not been currently established, and sensitivity and specificity for diagnosis have not yet been defined. The appearance of SCAD at CCTA can be subtle and can be missed, especially in distal small-caliber coronary arteries; hence utilization of other noninvasive imaging multimodalities may help solve this diagnostic challenge. Accurate and prompt diagnosis is vital, as management of SCAD differs significantly from that of traditional atherosclerotic acute coronary syndromes, with conservative management preferred for the majority of SCAD patients, and invasive treatment reserved for those with ongoing or recurrent ischemia, heart failure, or hemodynamic compromise. The goal of this review is twofold: (a) to discuss the potential role of CCTA in the diagnosis of SCAD, and (b) to discuss the role of multimodality imaging that may improve diagnostic yield, guide management, and enable subsequent surveillance. An invited commentary by Ordovas is available online. Online supplemental material is available for this article. ^©RSNA, 2021.

The Role of Imaging for MINOCA (Myocardial Infarction with No Obstructive Coronary Artery Disease): a Review of Literature and Current Perspectives

Purpose of Review

The objective of this review is to summarize scientific statements on the diagnosis and management of myocardial infarction with no obstructive coronary artery disease (MINOCA); define the diagnostic role of optical coherence tomography (OCT), intravascular ultrasound (IVUS), and cardiac magnetic resonance imaging (CMR); and provide representative case examples.

Recent Findings

The majority of patients with MINOCA are evaluated by conventional coronary angiography. However, intracoronary imaging using OCT or IVUS permits more accurate understanding of the underlying pathology. These and other imaging modalities provide significant diagnostic and prognostic value.

Summary

Although nonobstructive disease is the hallmark of the disease, MINOCA is associated with significant morbidity and mortality. Every effort to define the underlying pathology is necessary and requires more standardized use of imaging in clinical practice.

Intravascular Imaging in Acute Coronary Syndrome Patients without Significant Stenosis on Coronary Angiography

Intravascular coronary imaging has facilitated the field of interventional cardiology with multiple studies showing the superiority of intravascular image-guided percutaneous coronary interventions for the reduction of lesion revascularization rates. It also aids in understanding the mechanism of myocardial infarction with nonobstructive coronary artery disease. Despite such results, there is a slow adaptation of intravascular imaging use in the real world. We present two cases where intravascular imaging helped in the rapid understanding of the etiology of acute coronary syndrome and facilitated the management of both patients.

Spontaneous Coronary Artery Dissection (SCAD): Case Series and Mini Review

Spontaneous coronary artery dissection (SCAD) has gained recognition in recent years as a non-atherosclerotic cause of acute coronary syndrome (ACS), especially in young and middle-aged women without any of the classic risk factors for cardiovascular disease. The booming use of coronary angiography in patients presenting with ACS combined with new, revolutionary methods of intravascular imaging, have led to increased rates of SCAD diagnosis. We aim to present a brief, up-to-date review of the existing literature, along with our experience as reflected in the recent management of nine SCAD cases in three tertiary care hospitals.

Conservative management of severe coronary artery hematoma and dissection following stent implantation

Severe dissection and hematoma following stent implantation can cause acute vessel closure, which requires an immediate bailout procedure. However, bailout from such a situation may not be easy, especially when the hematoma extends to the distal segment of a coronary artery. We present a case of 73-year-old woman with effort angina who underwent PCI to the right coronary artery (RCA). Following stent implantation, there was a massive hematoma from the distal edge of the stent. We tried to create re-entry at the distal part of the hematoma, but were not successful. We managed her conservatively without additional stent placement or creating re-entry. Follow-up coronary angiography on day 68 showed excellent coronary flow. Intravascular ultrasound demonstrated complete healing of the hematoma. A hematoma caused by edge dissection is a challenging complication. Additional stent implantation to cover the entire length of the hematoma and/or cutting balloon dilatation to create re-entry are options; however, these procedures may worsen the situation. Our case clearly showed healing of dissection and hematoma without creating re-entry or additional stent implantation. Conservative management should be considered an option for severe edge dissection and hematoma following stent implantation.